The principle of operation of piston within a cylinder, is driving the piston in oscillating movement to reproduce motive force by combusting the fuel, theoretically, the piston must be completely sealed with the cylinder wall, so the combustion gas can be fully sealed from leaking so as being effectively used to drive the piston. However, the wear resistance between the piston and cylinder wall would be augmented due to the tightness of the oversized piston between the piston and cylinder wall, thus the operation temperature will be correspondingly increased whereas the lubricant adhered is greatly reduced, furthermore, such movement will result in piston scraping so as to shorten effective piston as well as cylinder life. While the piston is undersized by which the piston is not perfectly sealed against cylinder wall, the operation temperature is reduced and maintained at a lower degree, the nitric oxide and sulphur dioxide would be generated due to incomplete combustion, and are mixed with condensed vapor into a hazardous chemical compound which will substantially erode the cylinder.
In the prior arts, to secure piston size fitted within cylinder, numerous experiments would be conducted repeatedly towards varying size of cylinders, in order to determine the precising piston fitted in accordingly, such design will prolong the design cycle thus the cost will increase appreciably.
In view of the drawbacks of the prior art, the inventor of the present invention based on years of experience in the related industry to develop a piston device and its manufacturing method to overcome the drawbacks of the prior art.